Technique for Measuring Drive Belt Wear

The Honda Service manual says to check the belt for wear at 12000 miles and to change it at 16000 miles. The standard belt width is 1.10 inches with the wear limit at 1.06 inches. The differential between NEW to WORNOUT is only 0.04 inches - which is a bit over 1/32 of an inch - which is a mighty small number. From posts on this forum and my limited experience, it seems as if the belt does not (typically) actually 'wear out' - rather it just gets changed out - so this post is probably meaningless. However, I have tried unsuccessfully to track my drive belt wear rate - but like I said - measuring it may be meaningless. However, I have developed a method that now seems to give me reliable results as to whether I have reached the service limit - and that is the purpose of this post.

Tools you need:
1) Calipers (or something to accurately measure width) - I purchased a 6inch caliper from Harbor Freight Tools and use it for lots of accurate measurements on my SWing.
2) Plastic Pieces (2) to hold against side of belt - I used a couple of plastic picture hangers that I had in my tool box.
3) Plastic tab cut to 1.060 inches - I used the top of a deli food container top that I kept trimming until I got to 1.060 inches.

Technique:
Hold the plastic on the sides of belt - then place the 1.06 inch wide plastic on top of the belt - and if you can move it left to right any amount then your belt is wider than 1.06 inches - if not it is under 1.06 inches. Plus you can visually gauge how much it moves side to side to get a fairly accurate estimate of your actual belt width.

Below are two photos: one showing the tools (note caliper opened up to 0.04 inches - mighty small crack!). The other showing a belt that was taken off my SWing - but the technique works well for a belt still installed on a SWing. Using another technique I got a measurement once that showed the belt was BELOW the wear limit; however, with the above technique it showed it to be ABOVE the wear limit (so no need to replace belt) at 12,000 miles.

TOOLS YOU NEED



ACTUAL MEASUREMENT (the red in the photo is the plastic gauge - it is a bit hard to see - sorry about that. Also, I normally hold the plastic on the side so that they are level - but this was a bit hard to do while holding the camera)

Nice, what a clever idea.

Dimond

I wish I had read this post a few weeks ago. My drive belt disintegrated on me while crusing the highway heading to the house to visit my kid. Since I was coasting freely, I had no trouble changing lanes and pulling off to the (paved) side of the road. It took over an hour for a tow truck to come (and I learned to my sorrow that AAA does not provide motorcycle services in MA). I had him tow me to the house because when I bought the Swing last year I had converted the 2nd car garage into a small shop of sorts. It took more than a week for the new belt to come and when I finally went to install it and cleaned out the mess in the variator housing, I discovered that stress of the shredded belt winding itself around the drive shaft sleeve had caused one of the 4 tines in the OEM movable drive face(which is turned by the ramp plate) was sheared off. This means that only 3 of the 4 arms could turn the drive face - and I didn't know if that was advisable. Fortunately I held on to the J Costa. (I had bought Dr Pulley sliders not knowing anything about J Costa. My mechanic told me about it when he went to install the sliders last Winter.) So I reinstalled the J Costa - with the totally overused pins - and ordered a new OEM drive face. It's at the post office now and I'll pick it up on Monday.

The point is, if I had read this post earlier, I could have bought a caliper and took a read on my belt when I first installed the OEM variator. I would have saved myself a lot of grief. (On the other hand, I learned a lot of things and have gained confidence in making these repairs - so I guess it's not a total loss.)

My take on drive belts-----now with over 250,000 miles on rubber band drive scooters---I never go thru the trouble of measure/wear check. Just change at Honda recommended intervals---OEM. #2 carry spare belt/and tools to make change if necessary----dealers do not have belts/rollers in stock.

so far only one belt break underway---Helix at near end of service life of belt. Something to think about on belts---be prepared, have your won parts/ do own work----one belt break underway can be very expensive on trip....towing, waiting for parts/service.

How many miles on the belt when it let go ? I measure my belt directly on the driven clutch face with the same type of caliper. I place it on the top of the belt where the belt meets the face plates of the driven pulley. I check my belt every 10kL and will be replacing after the riding is over in october.

The belt was within 500 miles of end of service life----which if I remeber right was 15,000 miles on Helix. If I checked belt every 10 k(6250 mi) I would be spending too much time on lift. Even in bad years I ride 20-25,000 miles. Never put bike away in winter, even in WI or MN.

Another thing to consider on scooter drive belts-----they wear and have internal wear/stress you cannot see---age can be factor there, too. On my current new Burgman 400, I am already over the 14,500 mile recommended change interval---shooting for 20,000 and change....but carry spare new belt and tools to make change if necessary underway.

My one belt that broke was ground up in little pieces=mess.

Dimond, at last someone who measures in feet and inches, i thought iwas the only one left. Regarding the drive belt iam with John Grinsel he has a lot of experiance and i always take note of his advice.

I change my belt (myself) at no more that 16,000 mile interval - regardless of what wear 'life' may be on the belt. For just over $100 (for belt), I don't want to risk having it break down - either in some remote place - or even a few miles from home. Plus it sounds as if it can cause damage/mess if it does break.

MarkB wrote:

My drive belt disintegrated on me while crusing the highway

Mark - How many miles were on your belt?

john grinsel wrote:

carry spare new belt and tools to make change if necessary underway.

John - You carry everything necessary to change your belt on the side of the road? WOW - I am impressed! Doesn't that eat big time into your cargo carrying space?

Summary:
Based on this thread I am going to 'try' to bring along a spare belt - just in case as NO ONE STOCKS any SWing parts in Northern California and it seems to take days to get them - and any mechanic can easily change it for me (but if it breaks in the Sierra's then this is likely going to be an all day ordeal).

I got the bike last Sep with 14.4K miles on it. Less than a month later the variator light came on. (I panic'd a bit cause I was a newbe and didn't know how serious it was. After spending time on the blog here, I had my (newly found) mechanic change the belt (and tires, etc.). Say it had 15K on it. It now reads 24.4K - so, less than 10K miles on the belt. Needless to say, I was surprised when it happened. I will start to follow John's advice. I made the variator tool and I have a torque wrench which works nicely and they don't take up much room in my topbox. I'll just have to come up with another $100+ for another new belt. (sigh)

John has ridden a gazillion miles and only had one belt break. This is probably due to preventive maintenance and knowing his ride. I can see carrying an extra belt (maybe one you have changed that still has miles left), but I don't think it would be high on my list of concerns.

Does anybody know where I can get instructions on chnaging the drive belts? My indicator has been on for about a month and I ride about 120 miles a day

vbanks1956 wrote:

Does anybody know where I can get instructions on chnaging the drive belts? My indicator has been on for about a month and I ride about 120 miles a day

Look at the pictorials for variator belt change. Jeff did a pictorial for this.

Dimond

Are you sure about the measurements? I installed the new oem variator today and measured my belt with a digital caliper similar to yours. It measured 1.059"after just one month! Something does not seem right here. (I'll post pictures tomorrow, if I can.)

MarkB wrote:

Dimond

Are you sure about the measurements? It measured 1.059"after just one month! Something does not seem right here.

Hi Mark, The factory limits AND where you need to 'take' the measurement are specified in the Honda Service Manual. One method for obtaining the measurement for comparison to the factory limits is listed in this initial post; however, there are other methods you could use to get your measurement - but they need to give you an accurate measurement. IMO it is VERY difficult to get an accurate measurement to compare to the Honda factor limits - so lately I have just been running the belts up to the 16k change interval, then changing the belt - and forgetting about the dang measurement. So, regardless of your measurement, I am suggesting that you just run your scooter up to the 16k limit and change your belt at that point in time - and forget about measuring. By the way, did you follow the methodology in the initial post EXACTLY - or did you measure in some different manner? And if so, what was your method? In any event, IMHO there is a lot of inaccurate belt measuring going on and it is likely causing a lot of needless worry.

You're probably right about the difficulty in measuring it, Dimond. The belt appears to be tapered from the outside to the inside - probably to match the conical shape of the variator faces. I did not make the little 1.06" plastic tab you described. I just tried to measure the ouside surface of the belt directly with the caliper. Here's a picture of it.

I guess I can't post pictures anymore.

i can't figure out this picture hosting stuff. I used to be able to simply paste my photo to the post - now I can't.

Wait...
...maybe this will work.

@MarkB, You are not the only person to try that method but its not correct. I posted about it here: https://www.silverwing600.com/t4554-drive-belt-service-limit-measurement

RArch,

Thanks for that thread and the diagram. It really helps. The next time I open it up, I'll know how to measure it properly.

Dimond,

I now see the wisdom of your method. I will make something similar for my tool kit.

Hello!
The variator belt a couple of questions about it.
Really 27mm width to be replaced?
Mine is 25.5 mm wide crack destruction, I do not see anything on it.
This can cause some damage to the system's?
How to change the belt Wear of values ​​(eg, the same burning speed and another speed)?
Yellow indicator light on the instrument panel, on "V". ignition is approx. 1 second then turns off lighting. This indicates to me that you need to replace the belt?

Suggest you replace your belt AT LEAST every 16,000 miles as noted in Honda Service Manual. The 'variator light' goes on 16,00 miles after the last reset - it has nothing to do with the actual amount of belt wear - it is only a reminder that your belt needs to be changed and you should begin planning on getting it changed soon as Honda is recommending that it be changed after 16,000 miles of use; however, there is no magic number beyond 16,000 miles when your belt will either wear out or break - but why take the chance. My last belt was on for 19,000 miles and I did notice far less shuddering/thumping when the new belt was put in - in retrospect, I should have just changed it a 16,000 miles as Honda recommends. It is normal that your variator light go on for a second - then out. If it stays on continuously - then the belt needs to be changed. Some on this forum have reported their variator light coming on due to other causes - but it has not happened to me. I am not aware of any sensor on the SWing that would indicate belt wear. Measuring belt wear accurately, IMHO, is neither an easy task nor does it give reliable data. When I change my belt - and my tires - I order another one so I am ready for the next change-out as I can get the best prices on line and no one stocks these in Northern California.

I agree with you Dimond, i changed my belt at 16000mls when the light came on. I am at 26,000mls now and looking at having a belt ready for 32,000ml change. If you are inspecting the belt at these mileages surely it makes sense to just change it, if you have the covers off, to inspect.

Pigiboy: follow the link in my post above and have a read, maybe you have measured your belt incorrectly.

Also take a look at this: https://www.silverwing600.com/download.forum?id=315

I just change my belt every 16,000 miles for my own peace of mind. The last thing I want is for it to break and you are somewhere without an extra belt and the tools needed to change it. Most shops do not stock belts. We have a member - "Hammy" - that broke down in Indiana and I shipped him out a good used belt, just to get him home, but it also took another member of this board who lives in Indiana to help him install it.

Just my thought on it though.

JeffR_ wrote:

We have a member - "Hammy" - that broke down in Indiana and I shipped him out a good used belt, just to get him home, but it also took another member of this board who lives in Indiana to help him install it.

Wow Jeff, that was very good of you and the other member. Where is that story on the forum?

To measure wear limit with belt fitted I made this .......



With the red line added at 27mm groove width it is easy to see when "on the limit" .......




If anyone wants to make one,material (I used an offcut of 3mm thick Plexiglass) & most dimensions are academic,salient points are:
Width at base line .. 20mm
Side angle .. 14 degrees out of vertical

HTH

One fast way to check the belt and takes no space in the tool pouch...

Thanks...

Magoo

Magoo Silver wrote:

One fast way to check the belt and takes no space in the tool pouch...

Thanks...

Magoo

 Pleased to help bud  

Great tool design!

Cheers buddy   I should think others have done similar,just not thought to post it,being a newbie to scooter maintenance I just post everything I can't easily see on the forums

The Bern wrote:

Cheers buddy   I should think others have done similar,just not thought to post it,being a newbie to scooter maintenance I just post everything I can't easily see on the forums                                                                                                                    

And it is appreciated. Some of the newer members may not know that one of the reasons JeffR started this forum was because he was afraid information contained on another forum might be lost. Thanks Jeff and all the others who continue to add information.  

[/quote]>>one of the reasons JeffR started this forum was because he was afraid information contained on another forum might be lost.<< [/quote]

So true. There is lots of good information & How to's on this form. Unfortunately the archives are very difficult & confusing to navigate. For example I found it impossible to locate the post that I did a couple of years ago which showed a wiring diagram for a DIY 4 way flasher mod.

What would be nice here is a forum topic explaining how to properly use the archives function to locate previous posts on a given topic --even if you don't know the exact wording for the subject post.

When a new member writes in and asks a question regarding 'changing the belt' or wanting more acceleration, etc, referring them to the Archives just doesn't work.

How do we fix that?

Tim

It could be fixed by adopting the good old universal alphabetical indexing based on the basic part name. Another site I am on (Delica) went to this system due to the exact problem we are having here.
EG 1st split: Engine: then separate indexed files for various components as the info comes through.
2nd split: Transmission/belt drive :Then separate indexed files
3rd split: Forks etc etc
etc.
The hints and fixes could be selected for inclusion by the mods to stop non technical or superfluous
posts

http://www.delicaclub.com/viewtopic.php?f=3&t=14508

Unfortunately I am not a technophobe so I probably would stuff up the site if I tried to set it up.

I think measuring is waste of time....just change belt based on miles Honda recommends with OEM belt  and your chances of walking are low----however, bikes that are not ridden much maybe after a couple of years the belt needs a look at.  I ride a lot so I never have old belts on my scooters and after 300,000 miles on rubber band drive scooters and broken only one belt with belt still in service life (Helix)    I CARRY spare belt as most dealers do not have them in stock.